Fuse puller switch



M. GUETT .pril 13, 1937.

FUSE FULLER SWITCH Filed Oct. 30, 1935 2 Sheets-Sheet l INVENTOR MONROE GUETT BY H15 ATTORNEYS wdw April 13, 1937. M. GUETT 2,077,319

FUSE FULLER SWITCH Filed Oct. 30, 1935 2 Sheets-Sheet 2 almmula INVENTOR MONROE GUETT BY HIS ATTORNEYS Patented Apr. 13, 1937 UNITED STATES PATENT OFFICE FUSE PULLER SWITCH Application October 30, 1935, Serial No. 47,496

16 Claims.

This invention relates to electrical apparatus having fuses which are mounted upon a removable member or plug which has contacts engaging with fixed contacts of a receptacle or base whereby the fuses may be removed as a unit by removal of the plug from the receptacle portion of the device.

It is an object of my invention to provide an improved device of the above type which may be economically constructed and which will have a minimum number of parts of simple construction of which as many as possible maybe identical and interchangeable.

Another object of my invention is to provide 1 device of the above type in which the plug may be placed in a reserve open-circuit position without imposing stress upon the fuse receptacle contacts but at the same time having the fuses completely within the device and shielded against 20 contact from the outside.

Another object of my invention is to provide a device of the above type in which the plug may be reversed end-for-end and placed in the receptacle member with the fuses and current car- 5 rying parts of the plug shielded from contact from the outside, andin non-conducting position. Other objects and advantages of my invention will become apparent as it is described in connection with the accompanying drawings.

30 In the drawings:-

Figure 1 is a plan view of the receptacle portion of a device embodying the principles of my invention.

Figure 2 is a longitudinal section view of my invention taken on line 2--2 of Figure 1.

Figure 3 is an end elevation view partly broken away of the plug or fuse holder portion of a device embodying the principles of my invention.

Figures 4 and 5 are perspective detailed views 40 )f the two forms of finger contacts which are mounted upon the plug device.

Figure 6 is a longitudinal section taken on line 66 of Figure 1 showing the plug and receptacle portions of the device in assembled current-car- 45 rying position.

Figure 7 is a bottom plan view of the receptacle portion of the device.

Figure 8 is a transverse section taken along line 8-8 of Figure 1 showing the plug and receptacle 50 portions of the device when the plug is in storage position.

Referring to the drawings, it will be seen that the device comprises a base portion l0 formed of an insulating body such as porcelain or any other suitable insulating material. The body may be in the form of a rectangular block which is hollowed out from the top surface to provide a well lllw into which may fit a. plug device I2 hereinafter more particularly described. The base or receptacle portion l 0 of the device may have at each end extensions ll of less height than the main body of the block and these extensions l4 may each have a pair of parallel channels lfia and l6b for the reception of wire terminals l8 and 20 and terminal portions 22a, 24a, 26a and 28a. of receptacle contacts denoted generally by the numerals 22, 24, 26 and 28. These contacts may be stamped in strip form from sheet metal and are identical in size and shape and each has a contact portion bent into U-shape (e. g. 2812) at right angles to the terminal portion of the contact (e. g. 28a). To accommodate the u or contact portions of the receptacle contacts, pairs of apertures 30, 32 and 34, 36 are formed in the floor of the well lflw at each end in the neighborhood of the corners of the well. These apertures are connected by passages 38 with the wire terminal channels Mia and I6?) for passage of the terminal portions of the contacts.

Barriers 40 and 42 are provided in the longitudinal axis of the base I0 between the contacts 22, 24 and 26, 28 respectively, to prevent arcing between the contactsof each pair when the circuit is being broken. These barriers extend up perpendicularly from the floor of the well nearly to the top of the insulating block and run from the ends of the block inwards. All corresponding parts of the device as thus far described are arranged symmetrically on each side of the longitudinal axis.

In order to connect opposed contacts, such as contact 20 to contact 26, and 22, to 28, and at the same time provide a fuse or safety device in the circuit, which device may be removed when the circuit is broken or replaced when its function has been performed, there is provided a rectangular block of insulating material of any suitable composition, such as a phenolic condensation product. This block may have dimensions slightly less than the dimensions of the inside of the well low so that the plug device may fit snugly within the well. Preferably the thickness of the plug device will be less than the depth of the well in order to provide space for cartridge fuses within the well. The plug device has mounted upon it at each end pairs of finger contacts 52, 54 and 56, 58. Opposing contacts at each end of the plug device are identical, that is to say contacts 52 and 56 are identical and contacts 54 and 58 are identical. The form of the contacts 52 and 56 is shown in detail in Figure 4 and the form of contacts 54 and 58 is shown in detail in Figure 5. By reference to these figures it will be noted that each contact is L-shape, each having a contact portion, such as 540., and an anchor portion as 541), turned at right angles to the contact portion and provided with an internally threaded central aperture, as 540, for the reception of a securing screw 55 passing through the plug device 12. It will be noted that the contacts 52 and 56 have edgewise extensions from the left edge of the contact portion (e. g. 52c) and that the contacts 54 and 58 have edgewise extensions from the right edge of the contact portion (e. g. 54e) as seen in Figures 4 and 5 so that the contact portions, (e. g. 54a) are of greater Width than the anchor portions of the contacts. The contacts may conveniently be stamped from sheet metal.

To provide room for these edgewise extensions during the engaging of the finger contacts with the receptacle contacts, there are provided recesses 3%, 321*, 34r and 361 in the side walls of the apertures 30, 32, 34 and 36, the recesses 34r and 361 being in adjacent walls of the apertures 34 and 36 and the recesses 301* and 32r being in opposite walls of the apertures and 32. The recesses 301, 321', 341', 361", like the apertures 30, 32, 34, 36 are in the floor of the well. The reason for the opposite positioning of these recesses will become apparent when it is noted that the identical contacts 52 and 56 and 54 and 5B face oppositely when secured at their respective ends, thus positioning the edgewise extensions of the contacts 52 and 54 toward the outside of the plug device l2 and positioning the edgewise extensions with the contacts 56 and 58 adjacent one another toward the longitudinal axis of the plug device 12. It will thus become apparent that when attempt is made to insert the plug device [2 in the well low with the finger contact 58 directly over the receptacle contact 28, the plug device may be fully inserted in the well to bring contacts 52, 54, 56 and 58 into engagement with contacts 22, 24, 26 and 28 respectivelly, as illustrated in Figure 6.

In order to complete the circuit between the contact fingers 22 and 26, and between contacts 24 and 28, conventional fuse clips 23 may be provided and may be secured with their base portions in contact with the anchor portions of the contacts 52, 54, 56 and 58 by means of the same screws that secure these contacts to the plug device l2. A cartridge fuse (not shown) may then be inserted in these clips and will complete the circuit as will be readily understood by those skilled in the art.

It may be observed that due to the opposite p0- sitioning of the edgewise extensions of the various finger contacts and the opposite positioning of the recesses in the sides of the contact apertures if attempt is made to reverse, that is to say, turn end for end, the plug device and insert it in the well, then the contact fingers will be unable to engage the receptacle contacts by reason of the ends of the fingers engaging at their edgewise extensions with the fioor of the well in manner as indicated in Figure 8. In this figure it may also be seen that the main portions of the finger contacts overlie the receptacle contacts, but are prevented from coming in contact with the receptacle contacts.

This non-conducting position of the device illustrated in Figure 8 may be called the reserve or storage position. It is desirable that in this position of the device, the contact fingers, fuse clips, fuses and all current carrying parts be inaccessible and shielded against all outside contact. Therefore the height of the walls of the well and the thickness of the plug device and the heights of the finger contacts are proportioned so as to permit an overlap between the walls of the well and the walls of the plug device as illustrated in Figure 8.

Aligned channels 60 may be out along the longitudinal axis of the plug device on the surface thereof for the reception of the top portions of the barriers and 42, thus making it impossible for an arc to jump between the finger contacts and the receptacle contacts at the same end of the device when the plug is pulled away from the base portion.

It will be noted that both the plug portion and the base portion of my device are symmetrical about the longitudinal axis thereof, thus making it possible to duplicate the form of many of the parts and thereby reduce the manufacturing cost of the invention.

From the foregoing it will be observed that I have provided an improved form of fuse and switch device which is simple and economical in construction and positive in operation. My invention has the advantage of relieving the fuse clips of any strain when the device has its parts in conducting position or in storage position whether or not excessive force is applied to the device in either of these positions.

Many modifications within the scope of my invention will occur to those skilledin the art, therefore I do not limit the invention to the exact form of the parts as shown and described.

I claim:

1. In a device of the character described, an insulating body having a well with a plurality of apertures in each end of the bottom of the well, receptacle contacts within said apertures, each aperture having a recess offset into its side, the recesses at one end of the device being in the adjacent sides of the apertures and at the other end being in opposite sides of the apertures, in combination with a plug device adapted to fit closely within said well, finger contacts on said plug device adapted to engage with said receptacle contacts and having edgewise extensions adapted to fit within said recesses when said plug device is inserted in said well in a predetermined position and adapted to rest on the fioor of said well and overlie said apertures when said plug is reversed end-for-end.

2. In a device of the character described, an insulating body having a well with a plurality of apertures in each end of the bottom of the well, receptacle contacts within said apertures, each aperture having a recess offset into its side, the recesses at one end of the device being in the adjacent sides of the apertures and at the other end being in opposite sides of the apertures, in combination with a plug device adapted to fit closely within said well, finger contacts on said plug device adapted to engage with said receptacle contacts and having edgewise extensions adapted to fit within said recesses when said plug device is inserted in said well in a predetermined position and adapted to rest on the fioor of said well and overlie said apertures when said plug is reversed end-for-end, and fuse holding means electrically connected with said contact fingers, said means being entirely shielded from outside contact in said predetermined and said reversed positions by overlapping portions of said body and plug device.

3. In a device of the character described, an insulating body having a well with a plurality of apertures in each end of the bottom of the well, receptacle contacts within said apertures, each aperture having a recess ofiset into its side, the recesses at one end of the device being in the adjacent sides of the apertures and at the other end being in opposite sides of the apertures, in combination with a plug device adapted to fit closely within said well, finger contacts on said plug device adapted to engage with said receptacle contacts and having edgewise extensions, said fingers and extensions being located symmetri-' cally with respect to the longitudinal axis of said plug device, and said recesses apertures and receptacle contacts being arranged symmetrically with respect to the longitudinal axis of said insulating body, said extensions being adapted to fit within said recesses when said plug device is inserted in said well in a predetermined position and adapted to rest on the floor of said well and overlie said apertures when said plug is reversed end-for-end.

4. In a device of the character described, an insulating body having a well with a plurality of apertures in each end of the bottom of the well, receptacle contacts within said apertures, each aperture having a recess offset into its side, the recesses at one end of the device being in the adjacent sides of the apertures and at the other end being in opposite sides of the apertures, in combination with a plug device adapted to fit closely within said well, finger contacts on said plug device adapted to engage with said receptacle contacts and having edgewise extensions, said fingers and extensions being located symmetrically with respect to the longitudinal axis of said plug device and said recesses apertures and receptacle contacts being arranged symmetrically with respect to the longitudinal axis of said insulating body, said extensions being adapted to fit within said recesses when said plug device is inserted in said well in a predetermined position and adapted to rest on the floor of said well and overlie said apertures when said plug is reversed end-for-end, and a fuse holding means electrically connected with said contact fingers, said body and plug device having overlapping portions entirely shielding said means and said contact fingers from outside contact in said predetermined and said reversed positions.

5. In a device of the character described, an

' insulating body having-a well with a plurality of contact openings in each end of the bottom of the well, the openings at the same end being arranged symmetrically with respect to the longitudinal axis of the body, but the openings at the opposite ends though on the same side of the longitudinal axis being spaced unequally from said longitudinal axis, receptacle contacts within said openings, in combination with a plug device adapted to fit within said well, finger contacts on said plug device, the finger contacts at the same end being arranged symmetrically with respect to the longitudinal axisof the device but the finger contacts at opposite ends though on the same side of the longitudinal axis being unequally spaced from the said longitudinal axis, said finger contacts being adapted to engage with said receptacle contacts when said plug device is placed in said well in a predetermined position and adapted to rest on the floor of said well out of contact with said receptacle contacts when said plug device is reversed end-for-end.

6. In a device of the character described, an insulating body having a well with a plurality of contact openings, in each end of the bottom of the well, the openings at the same end being arranged symmetrically with respect to the longitudinal axis of the body, but the openings at the opposite ends though on the same side of the longitudinal axis being spaced unequally from said longitudinal axis, receptacle contacts within said openings, in combination with a plug device adapted tofit within said well, finger contacts on said plug device, the finger contacts at the same end beirg arranged symmetrically with respect to the longitudinal axis of the device but the finger contacts at opposite ends though on the same side of the longitudinal axis being unequally spaced from said longitudinal axis, said finger contacts being adapted to engage with said receptacle contacts when said plug device is placed in said well in a predetermined position, and adapted to rest on the floor of said well out of contact with said receptacle contacts when said plug device is reversed end-for-end, and a fuse holding means electrically connected With said contact fingers, said body and plug dew'ce having overlapping portions entirely shielding said means and said contact fingers from outside contact in said predetermined and said reversed positions.

7. In a device of the character described, an insulating body having a Well, a plurality of receptacle contacts in the bottom of said well arranged symmetrically with respect to the longitudinal axis of said body, in combination with a plug device adapted to fit within said well, finger contacts arranged symmetrically with respect to the longitudinal axis of the plug device, the contact portions of said finger contacts at opposite ends of the device being unequally spaced from said longitudinal axis, said finger contacts engaging with said receptacle contacts when said plug device is inserted in said well in a predetermined position, and means on said body engaging with said finger contacts when said plug device is reversed end-for-end and inserted in said Well, said means holding said finger and said receptacle contacts from engagement.

8. In a device of the character described an insulating body having a well, a plurality of receptacle contacts in the bottom of said well arranged symmetrically with respect to the longitudinal axis of said body, in combination with a plug device adapted to fit within said well, finger contacts arranged symmetrically with respect to the longitudinal axis of the plug device said finger contacts engaging with said receptacle contacts when said plug device is inserted in said well in a predetermined position, and means unequally spaced from the longitudinal axis of said body and said plug device and acting to hold said finger and receptacle contacts from engagement when said plug device is inserted in said well in position reversed end-for-end from said predetermined position.

9. In a device of the character described, an insulating body having a well, a plurality of receptacle contacts in the bottom of said well arranged symmetrically with respect to the longitudinal axis of said body, in combination with a plug device adapted to fit within said well, finger contacts arranged symmetrically with respect to the longitudinal axis of the plug device, said finger contacts engaging with said receptacle contacts when said plug device is inserted in said well in a predetermined position, and means unequally spaced from the longitudinal axis oi said body and said plug device and acting to hold said finger and receptacle contacts from engagement when said plug device is inserted in said well in position reversed end-for-end from said predetermined position, and a fuse holding means electrically connected with said contact fingers, said body and plug device having overlapping portions entirely shielding said means and said contact fingers from outside contact in said predetermined and said reversed positions.

10. In a device of the character described an insulating body having a well, a plurality of receptacle contacts in the bottom of said well arranged symmetrically with respect to the longitudinal axis of said body, in combination with a plug device adapted to fit within said well, finger contacts arranged symmetrically with respect to the longitudinal axis of the plug device, the contact portions of said finger contacts at opposite ends of the device being unequally spaced from said longitudinal axis, said finger contacts engaging with said receptacle contacts when said plug device is inserted in said well in a predetermined position, and means on said body engaging with said finger contacts when said plug device is reversed end-for-end and inserted in said well, said means holding said finger and said receptacle contacts from engagement, and fuse holding means electrically connected with said contact fingers, said body and plug device having overlapping portions entirely shielding said means and said contact fingers from outside contact in said predetermined and said reversed positions.

11. In a device of the character described, an insulating body having a well with apertures in the ends of the bottom of the well, receptacle contacts within the apertures, each aperture having a recess offset into one side, in combination with a plug device adapted to fit closely within said well, finger contacts on said plug device and adapted to engage with said receptacle contacts and having edgewise extensions adapted to fit within said recesses when said plug device is inserted in said well in a predetermined position and adapted to rest on the fioor of said well and overlie said aperture when said plug is reversed end-for-end.

12. In a device of the character described, an insulating body having a well with apertures in the ends of the bottom of the well, receptacle contacts within the apertures, each aperture having a recess oifset into one side, in combination with a plug device adapted to fit closely within said well, finger contacts on said plug device and adapted to engage with said receptacle contacts, and having edgewise extensions adapted to fit within said recesses when said plug device is inserted in said well in a predetermined position and adapted to rest on the floor of said well and overlie said aperture when said plug is reversed endfor-end, and fuse holding means electrically connected with said contact fingers, said means being entirely shielded from outside contact in said predetermined and said reversed positions by overlapping portions of said body and plug device.

13. In a device of the character described, an insulating body having a well with openings in the ends of the bottom of the well, receptacle contacts within said openings, said receptacle contacts being of less width than and positioned at one side of said openings, in combination with a plug device, finger contacts on said plug device of width approximately equal to said openings and adapted to engage with said receptacle contacts when said plug device is inserted in said well in a predetermined position, said fingers resting on the fioor of said well out of engagement with said receptacle contacts when said plug device is reversed end-for-end and inserted in said well.

14. In a device of the character described, an insulating body having a well with openings in the ends of the bottom of the well, receptacle contacts within said openings, said receptacle contacts being of less width than and positioned at one side of said openings, in combination with a plug device, finger contacts on said plug device of width approximately equal to said openings and adapted to engage with said receptacle contacts when said plug device is inserted in said well in a predetermined position, said fingers resting on the fioor of said well out of engagement with said receptacle contacts when said plug device is reversed end-for-end and inserted in said well, and fuse holding means electrically connected with said contact fingers, said body and plug device having overlapping portions entirely shielding said means and said contact fingers from outside contact in said predetermined and said reversed positions.

15. In a device of the character described, an insulating body having a well with openings in the ends of the bottom of the well, receptacle contacts within said openings, in combination with a plug device, finger contacts on said plug device adapted to engage with said receptacle contacts when said plug device is inserted in said well in a predetermined position, said openings being so positioned and arranged that when said plug device is reversed end-for-end and inserted in said well said fingers will rest upon the fioor of the well out of engagement with said receptacle contacts.

16. In a device of the character described, an insulating body having a well with openings in the ends of the bottom of the well, receptacle contacts within said openings, in combination with a plug device, finger contacts on said plug device adapted to engage with said receptacle contacts when said plug device is inserted in said well in a predetermined position, said openings being so positioned and arranged that when said plug device is reversed end-for-end and inserted in said well said fingers will rest upon the floor of the well out of engagement with said receptacle contacts, and fuse holding means electrically connected with said contact fingers, said body and plug device having overlapping portions entirely shielding said means and said contact fingers from outside contact in said predetermined and said reversed positions.

MONROE GUET'I'. 

